Test on Durability of Shield Tunnel Concrete Segment under Coupling Multi-Factors

Abstract

To study the durability of shield tunnel concrete segment under coupling multi-factors, the durability and degradation law of reinforced concrete segments under the joint action of carbonation, sulfate, chloride salt and stray current was studied by accelerated environmental and direct current (DC) power simulation test. The results show that the presence of the stray current not only accelerates the migration of chloride ions to the concrete, but also makes chlorine ion gradually converge to the steel surface. The steel corrosion near the corrosion solution on the up surface of segment is more serious than the steel corrosion near the carbon dioxide on the lower surface. The interaction of chlorine ions and stray current primarily controls the durability of the segment.